It appears you’re running around the forum expending a lot of needless mental energy on stuff that could be solved simply by contacting Oanda & Interactive Brokers & speaking with one of their customer services reps.
Have you not thought of either firing off an e-mail, clicking on any live support facility if available, or even picking up the phone & perhaps speaking to a rep from the two companies to voice your concerns?
After all, you make it quite clear by your comment below that you’re a little reticent about accepting advice & comment from other folk on a web site.
If that’s the case then why not use your initiative & go direct to the source. In your case it’ll save you time, energy & prevent you running around the forum like a headless chicken.